The use of a Van Norman dividing head for indexing is well known to the skilled machinist. The dividing head provides increments of six (6) minutes of rotation for the chuck.
For different indexing increments, a special dividing plate is used. This dividing plate has several concentric circles of indexing holes disposed on a face thereof. Such a dividing plate can be seen in the Patent to J. Y. Scott et al, U.S. Pat. No. 2,059,753; issued: Nov. 3, 1936.
While the aforementioned dividing plate does an adequate job of providing different indexing capabilities, it does not have any means for further dividing the increments into finer subdivisions.
The present invention seeks to provide a simple attachment for the dividing plate of the Van Norman dividing head, which will easily provide an increased indexing capability.
The invention uses a principle similar to that shown in the protractor of CROSS, U.S. Pat. No. 2,718,062; issued: Sept. 20, 1955.